Long Range Wireless Alarm System Based on LoRa and TOF LiDAR

This paper presents preliminary design of a long-range wireless alarm system. It discusses two schemes for long-range wireless network in different situations, then shows the hardware design of the alarm system. The system designed with Espressif ESP32-WROOM-32 microcontroller and Ai-Thinker Ra-02 LoRa module based on Semtech SX1278, which is separate into sender side and receiver side. In sender side, a TOF Lidar distance sensor is used to calculating the real-time distance at high speed. Once an object approaches and the distance calculated by TOF Lidar below the alarm threshold, the sender side will distribute a specific LoRa packet. In the meanwhile, the receiver recognizes the packet to trigger the alarm module.